Technical Field
The present invention relates to a vehicle seat.
Related Art
A technology is disclosed in, for example, Japanese Patent Application Laid-Open (JP-A) No. 2004-116654, in which a dynamic damper (a vibration damping device) is provided at a vehicle seat. The dynamic damper is constituted with plural damper masses, adjacent damper masses are connected to one another by a rubber member, and the damper masses are made capable of rocking via the rubber member.
Vibrations during running of an automobile and during idling can be transmitted to a vehicle seat through vehicle body connection portions (seat brackets) that fix the vehicle seat to a vehicle body floor portion.
Consequently, the vehicle seat vibrates. However, when the dynamic damper is provided at the vehicle seat, the damper masses rock when the vehicle seat vibrates, as a result of which the vibrations of the vehicle seat are damped.
In this conventional technology, because the dynamic damper is constituted with plural damper masses and the adjacent damper masses are connected to one another by the rubber member, degrees of freedom when the individual damper masses rock during vibration are high. Thus, it is hard to specify a natural oscillation frequency for the dynamic damper. Consequently, a vibration damping effect in the vehicle seat may not be provided satisfactorily.
Moreover, because the rubber member is used in this dynamic damper, a stroke of the damper masses during vibration is small and vibration damping amounts may not be large. Increasing the masses of the damper masses in order to increase vibration damping amounts can be considered. However, in this case the damper masses become larger and, in correspondence with the amount by which the damper masses become larger, it becomes more difficult to reserve space for disposing the dynamic damper equipped with the dynamic masses in the vehicle seat. In addition, if the masses of the damper masses are increased, there is concern that the vibration damping effect may decline with degradation of the rubber member(s).